Emerson Thome has been challenged to show that he can handle the likes of Wayne Rooney and Duncan Ferguson this weekend if he wants to secure a move to Rangers.

The Sunderland defender, who is available on a free transfer, has impressed during his trial spell at Ibrox and has caught the eye of manager Alex McLeish with some commanding performances on the club's pre-season tour of Germany.

Thome, who is competing with former Manchester United star David May to win a contract with the Scottish champions, had hoped that a decision on his future would be made this week.

But McLeish is keen to set the Brazilian a stiffer test than those posed by Rangers' Bundesliga Second Division opponents and will ask Thome to extend his spell in Glasgow in order to face Everton in a friendly at Ibrox on Saturday.

"I will talk to the boys about staying on for the Everton game," said McLeish, who admits he needs to sell players before he can hope to make a move for Thome's Stadium of Light teammate Kevin Phillips.

"I don't think there have been sufficient tests for Thome and May because German sides don't tend to play the aerial game which is largely prevalent in Britain.

"I know that both players have coped with this kind of thing in the past but they have both had injuries and I have got to be certain.

"I don't know if big Duncan Ferguson will be back in the scheme of things but English teams always pose a threat at set-pieces. They are notoriously big so I would like to see David and Emerson tested in this environment.

"It's one area of the team we have tried to strengthen in the last year in terms of our presence. Safe to say the two lads have done well so far but I would like them to remain with us and play in the Everton game."

Although he has made just one Premiership start in 18 months, Thome remains one of Sunderland's highest earners and is a player chairman Bob Murray is determined to offload as he attempts to manage the club's crippling debts.

But the &#xA3;4.5m defender's long-term fitness remains in question, with a string of serious knee problems having taken their toll on the South American, and McLeish will take no chances.

Rangers will play the final match of their trip to Germany this evening when they take on Regensburg. Thome and May are both expected to feature.